The U.S. Department of Energy said Friday that it welcomes the decision by oil and gas industry supplier Baker Hughes to disclose all chemicals in hydraulic fracturing fluid.

But Halliburton, a major competitor in the field, isn’t committing to such disclosure.

Deputy Assistant Energy Secretary Paula Gant said that Baker Hughes’ move “is an important step in building public confidence” and the department “hopes others will follow their lead.”

The oil and gas industry has said the fracking chemicals are disclosed at tens of thousands of wells, but environmental and health groups and government regulators decry a loophole that allows companies to hide chemical “trade secrets.”

Houston-based Halliburton said Friday that it’s studying the move by Baker Hughes, which is also based in that city. Halliburton said it had an interest in protecting “our intellectual property and the substantial investment it represents” and will examine the new Baker Hughes format for its ability to protect such investments.

Baker Hughes said it now believes it’s possible to disclose 100 percent “of the chemical ingredients we use in hydraulic fracturing fluids without compromising our formulations,” to increase public trust.

Baker Hughes spokeswoman Melanie Kania wrote in an email that it will take “several months” for the new policy to take effect. She said the end result will be a “single list” that provides “all the chemical constituents” for frack fluids, with no trade secrets.

A boom in drilling has led to tens of thousands of new wells being drilled in recent years using the fracking process. A mix of water, sand and chemicals is forced into deep underground formations to break rock apart and free oil and gas. That’s led to major economic benefits but also fears that the chemicals could spread to water supplies.

The mix of chemicals varies by company and region — and some of the chemicals are toxic and could cause health problems in significant doses — so the lack of full transparency has worried landowners and public health experts.

Many companies voluntarily disclose the contents of their fracking fluids through FracFocus.org, a website partially funded by the oil and gas industry that tracks fracking operations nationwide. But critics say the website has loose reporting standards and allows companies to avoid disclosure by declaring certain chemicals as trade secrets.